If you are at all handy check all of the guts of the toilet. That is, check the parts inside the tank as I mentioned above. If you still can't find any problems you should probably call a plumber. If you have two toilets back to back it sounds like you have a clog between the toilet and the main stack.
Scientists in Barcelona claim to have shown for the first time that unborn babies can hear in the womb at just 16 weeks gestation. They recruited pregnant women from 14 to 39 weeks' pregnant for the study, playing music both via headphones around the bump, and via a device inserted into the vagina.
By nine weeks, a developing fetus can hiccup and react to loud noises. By the end of the second trimester it can hear. Just as adults do, the fetus experiences the rapid eye movement (REM) sleep of dreams. The fetus savors its mother's meals, first picking up the food tastes of a culture in the womb.